<!DOCTYPE html>
<html>
 <head>
 <script type="text/javascript" src="jquery-1.7.2.js"></script>
 <script type="text/javascript">
 $(document).ready(
  function(){
 $("#txt").bind(
 "change",function(){$("body").css("background-color","#FF0000")
	 });
 });
 
 </script>
 </head>

 <body>
 <input type="text" id="txt">If you click on me, I will disappear.</input>
 </body>

 </html>